The VW Passat is a mid-size sedan or station wagon favored by higher end shoppers looking for a reliable luxury car. Under the hood, you'll find most of the components covered with a black cover. The battery is located on the driver's side, just over the fender. Replace the battery if it has a low reading on the battery-testing meter or you see a white chalky substance forming under the cover.
Pop the cover off the battery with a flathead screwdriver.
Remove the cables from the battery terminals with a battery terminal puller, taking off the negative cable first.
Lift the battery out of the compartment and safely dispose of the used battery at an auto parts store or bring it to a recycling center.
Use a wire brush to clean the tray that holds the battery. Wipe it off with a damp cloth and let it dry before replacing new battery. Dispose of the rags since they're covered with acid.
Clean the insides of the connector cables with a pointed wire brush. Keep your gloves on at all times to avoid getting acid on your hands and wear glasses or goggles to protect your eyes.
Place the new battery on the battery tray. Attach the correct cable on each terminal and tighten securely with pliers or socket wrench.
Replace the cover by pushing firmly down on it over the battery compartment.
Some newer Passats come with a 2-year warranty on the battery.